Increased Postprandial Colonic Motility and Autonomic Nervous System Activity in Patients With Irritable Bowel Syndrome: A Prospective Study

BACKGROUND/AIMS: The prevalence and severity of irritable bowel syndrome (IBS) declines with age, but the cause of this is unknown. This study tested 2 hypotheses: (1) autonomic nervous system responses to eating and bowel distention, measured by heart rate variability (HRV), differs by age in IBS patients and (2) HRV is correlated with colonic motility and IBS symptoms. METHODS: One hundred and fifty-six Rome III positive IBS patients and 31 healthy controls underwent colonic manometry with bag distention in the descending colon, followed by ingestion of an 810-kcal meal. HRV, evaluated by low frequency (%LF; 0.04–0.15 Hz) component, high frequency (%HF; 0.15–0.40 Hz) component, and the LF/HF ratio, was measured during colonic distention and after the meal. Motility index and subjective symptom scores were simultaneously quantified. RESULTS: Both colonic distention and eating decreased %HF and increased the LF/HF ratio, and both indices of autonomic nervous system correlated with age. In IBS patients, %HF negatively correlated with the postprandial motility index after adjusting for age. The %HF and LF/HF ratios also correlated with psychological symptoms but not bowel symptoms in IBS patients. CONCLUSION: Decreased vagal activity is associated with increase in age and greater postprandial colonic motility in patients with IBS, which may contribute to postprandial symptoms.

What Is New in Rome IV

Functional gastrointestinal disorders (FGIDs) are diagnosed and classified using the Rome criteria; the criteria may change over time as new scientific data emerge. The Rome IV was released in May 2016. The aim is to review the main changes in Rome IV. FGIDs are now called disorders of gut-brain interaction (DGBI). Rome IV has a multicultural rather than a Western-culture focus. There are new chapters including multicultural, age-gender-women’s health, intestinal microenvironment, biopsychosocial, and centrally mediated disorders. New disorders have been included although not truly FGIDs, but fit the new definition of DGBI including opioid-induced gastrointestinal hyperalgesia, opioid-induced constipation, and cannabinoid hyperemesis. Also, new FGIDs based on available evidence including reflux hypersensitivity and centrally mediated abdominal pain syndrome. Using a normative survey to determine the frequency of normal bowel symptoms in the general population changes in the time frame for diagnosis were introduced. For irritable bowel syndrome (IBS) only pain is required and discomfort was eliminated because it is non-specific, having different meanings in different languages. Pain is now related to bowel movements rather than just improving with bowel movements (ie, can get worse with bowel movement). Functional bowel disorders (functional diarrhea, functional constipation, IBS with predominant diarrhea [IBS-D], IBS with predominant constipation [IBS-C], and IBS with mixed bowel habits) are considered to be on a continuum rather than as independent entities. Clinical applications such as diagnostic algorithms and the Multidimensional Clinical Profile have been updated. The new Rome IV iteration is evidence-based, multicultural oriented and with clinical applications. As new evidence become available, future updates are expected.

Validity and Reliability of the Japanese Version of the Rome III Diagnostic Questionnaire for Irritable Bowel Syndrome and Functional Dyspepsia

BACKGROUND/AIMS: Reliable diagnostic instruments for measuring the presence of functional gastrointestinal disorders based on the Rome III criteria have been lacking in Japan. The aims of the present study were to translate and validate the Rome III diagnostic questionnaire which was widely used in Western countries. METHODS: The original version of Rome III diagnostic questionnaire was translated from English into Japanese through 3 independent forward translations, resolution, back translation and reconciliation of the differences. Forty-nine patients with irritable bowel syndrome (IBS), 32 patients with functional dyspepsia (FD) and 56 subjects without any current GI symptoms as controls were recruited from three hospitals located in different regions of Japan and completed the IBS and FD diagnostic modules twice within 14 days. Kappa statistic was used to assess test-retest reliability. The sensitivity and specificity of each diagnostic module for distinguishing IBS or FD patients from controls was tested. RESULTS: Median kappa statistics were 0.63 for the translated IBS diagnostic module and 0.68 for the FD module. The sensitivity, specificity, and positive predict value of the IBS module against physician diagnosis was 61.2%, 100%, and 100% and those of the FD module was 53.2%, 98.2%, and 94.4%, respectively. Meanwhile, IBS patients were significantly more likely to report blood in stools compared to controls (18.4% vs 1.8%, P < 0.01). CONCLUSIONS: The IBS and FD diagnostic modules on the Japanese version of the Rome III diagnostic questionnaire are valid and reliable. Further studies are warranted to elucidate the diagnostic utility of the red flag questionnaire.

Prevalence of narcotic bowel syndrome in opioid abusers in Iran

In spite of the increasing trend in opioid abusers worldwide, the prevalence of narcotic bowel syndrome [NBS] is undetermined. We aimed to estimate the prevalence of NBS and other opioid bowel dysfunction [OBD] in opioid abusers in Kerman, southeast Iran. According to the best of our knowledge, this is the first study to assess the prevalence of NBS in opioid abusers. By referring to addiction treatment centers in Kerman city and in a cross-sectional study, 577 subjects with opium or opioid subtracts abuse were included in our study. A validated questionnaire was used for OBD assessment and diagnosis of NBS was made according to both the presence of chronic abdominal pain despite increasing the opioid dose and ruling out other causes of abdominal pain. SPSS software version 16 was used for data analysis. p value<0.05 was considered as statistically significant. Constipation, regurgitation, and heartburn were the most gastrointestinal complaints that were found in 132[22.9%], 123[21.3%] and 91[15.8%] subjects, respectively. Only 16[2.8%] participants fulfilled all the NBS criteria. Simultaneous use of non-narcotic sedative drugs increased the risk of NBS significantly [the odds ratio 3:1 and p=0.049]. NBS is not rare among opioid abusers and should be considered as a cause of chronic abdominal pain in this group

Anti-Enteric Neuronal Antibodies and the Irritable Bowel Syndrome

BACKGROUND/AIMS: Functional gastrointestinal disorders are those in which no abnormal metabolic or physical processes, which can account for the symptoms, can be identified. The irritable bowel syndrome (IBS) is a significant functional disorder, which affects 10-20 percent of the population worldwide. Predominant symptoms of IBS are abnormal defecation associated with abdominal pain, both of which may be exacerbated by psychogenic stress. Our study was designed to test a hypothesis that symptoms in a subset of patients with a diagnosis of IBS are associated with an autoimmune degenerative neuropathy in the enteric nervous system. METHODS: Serum was collected from Rome II-IBS patients and controls at the University of North Carolina Functional Gastrointestinal Diseases Center. Assay procedures were immunohistochemical localization of antibody binding to enteric neurons and human protein microarray assay for antigens recognized by antibodies in the sera. RESULTS: Eighty-seven percent of IBS sera and 59% of control sera contained anti-enteric neuronal antibodies. Antibody immunostaining was seen in the nucleus and cytoplasm of neurons in the enteric nervous system. Protein microarray analysis detected antibody reactivity for autoantigens in serum with anti-enteric neuronal antibodies and no reactivity for the same autoantigens in samples not containing anti-enteric neuronal antibodies in our immunostaining assay. Antibodies in sera from IBS patients recognized only 3 antigens out of an 8,000 immunoprotein array. The 3 antigens were: (1) a nondescript ribonucleoprotein (RNP-complex); (2) small nuclear ribonuclear polypeptide A; and (3) Ro-5,200 kDa. CONCLUSIONS: Results of the present study suggest that symptoms in a subset of IBS patients might be a reflection of enteric neuronal damage or loss, caused by circulating anti-enteric autoimmune antibodies.

Biopsychosocial Model of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a common chronic disorder seen in gastroenterology and primary care practice. It is characterized by recurrent abdominal pain or discomfort associated with disturbed bowel function. It is a heterogeneous disorder with varying treatments, and in this regard physicians sometimes struggle with finding the optimal approach to management of patients with IBS. This disorder induces high health care costs and variably reduces health-related quality of life. IBS is in the class of functional gastrointestinal disorders, and results from dysregulation of central and enteric nervous system interactions. Psychosocial factors are closely related to their gut physiology, associated cognitions, symptom manifestations and illness behavior. Therefore, it is important for the physician to recognize the psychosocial issues of patients with IBS and in addition to build a good patient-physician relationship in order to optimize treatment. This review focuses on the interaction between psychological and physiological factors associated with IBS by using a biopsychosocial model. In this article, we describe (1) the predisposing psychological features seen in early life; (2) the psychological factors associated with life stress, the symptom presentation, and their associated coping patterns; (3) gut pathophysiology with emphasis on disturbances in motility, visceral hypersensitivity and brain-gut interactions; and finally (4) the clinical outcomes and effective treatments including psychotherapeutic methods.